PCV valve

[plee4139]

Has anyone installed a PCV valve on a 289 engine? I'm told it eliminates fumes and polutes less. Also, how would this affect the authenticity of my car?

[Mike Van Veghten]

Yes
Yes
Yes
Depends on how you install it.

Mike

[Skip Lackie]

PCV valves were required on all 1962-model cars sold in California, and all 1963 and later cars sold throughout the US and Canada -- so plenty of 289 engines came with them as standard equipment. The 59-64 parts book shows how they were connected. They were a little different in each year.

[jclary]

I too am interested in this topic. However, my thinking is that if you "retro-fit" a draft tube engine with a pcv valve, shouldn't you keep the draft tube? Additionally, what volume of air could you accomplish with pcv venting and not upset the fuel to air ratio and cause erratic engine performance similar to what you get with a manifold vacuum leak? I would like to experiment with it but I just don't think you could move enough air without causing the engine to stumble. Then there is the issue of fouling the plugs with the closer plug gap and lower coil power of the older engines and at what point in the manifold do you install the pcv intake for even distribution?

[mrobertweiss]

the pcv valve pintle controls what is in essence a controlled vacuum leak. These are often specific for the engine in question. A catch can will collect any oil and water droplets.The valve covers on some engines have breather ports/oil filler caps. These need to be baffled.The valley cover fore and aft have a place to vent or fill from, the standoff in front, the port just in front of the distributor, in the rear. I did alot of research on this issue for a turbocharged 289 project, because the boost pressures are an issue. The R2 supercharged engine has a PCV at manifold intake behind the carb, is routed thru a parallel tube to the crankcase on factory models, to the side of the oil pan. There are breathers on the valve covers. I do not yet know if my rather convoluted system , rigged on the project car, will be effective. Thanks, m weiss

[Tom Bredehoft]

I jury rigged a PVC on my '55 when I installed a '63 289. I went to CarQuest, found a valve that would fit, (90 deg. bend, two 3/8 tubes, short) and plumbed it between the valley cover adapter and the port on the back of the carb. I understand that it is only taking some of the fumes out of the valley, since I still have the oil fill pipe in the front, but that's all the draft tube would have been scavenging, any way. I haven't opened the engine since the installation, so I have no way of knowing how effective it is. I just hope for the best.

[gohdes]

I too am interested in this topic. However, my thinking is that if you "retro-fit" a draft tube engine with a pcv valve, shouldn't you keep the draft tube?

I bought a 60 lark (with a 259 v-8) from California, that had a PCV valve installed in a rubber hose between the intake manifold over cylinder #7 and the oil filler tube cap. Then they pinched the draft tube 95% closed. My piston rings failed on cylinder #7 and it filled with oil and was leaking like a seive, and had to have an engine rebuild. My mechanic suggested removing that PCV valve and opening up the draft tube again since he thought it possibly was causing a problem being over that cylinder. I bought a new oil filler cap without a hose nipple on it. Haven't really driven it much to see if it's working or not, I guess time will tell.

[StudeRich]

If you connect the PCV as the factory did on 1961 Calif. cars and '62 to early '64 U.S. wide cars, it will work fine, no issues. The PCV needs to be connected from the Lifter Cover to the rear lower bottom of the Carb. as all Carter, Stromberg and aftermarket Edelbrocks Carbs. have a 3/8" tube for hose or 3/8" Pipe tapped holes for, as used on '62-'64 V-8's. This is a very simple setup as shown in the '59-'64 Chassis Parts Catalog.

Just be sure that the replacement PCV Valve for the NLA original Carter you use is similar in port size and FLOWS TO the Carb. as many GM applications do not flow the correct direction if using the original '64 Lifter cover with the threaded pipe conn. on the cover that needs to flow from the threaded end to the hose end.

[jclary]

If you connect the PCV as the factory did on 1961 Calif. cars and '62 to early '64 U.S. wide cars, it will work fine, no issues. The PCV needs to be connected from the Lifter Cover to the "after the throttle" lower bottom of the Carb. as all Carter, Stromberg and aftermarket Edelbrocks Carbs. have 3/8" Pipe tapped holes for, as used on '62-'64 V-8's. This is a very simple setup as shown in the '59-'64 Chassis Parts Catalog.

That is a great point Rich, however, I wonder how truly effective these early systems were. I just can't wrap my brain around how the tiny pcv valve could "vent" sufficient "volume" without upsetting the balance of fuel to air ratio. If they were all that effective, I doubt that we would have seen the addition of "Top-side" vents where the ventilation was routed into the air cleaner like my '72 El-cameno, my '79 Jeep, '87 Nissan and many others. Then there were those mysterious funky "Air Pumps" that channelled the vents into the exhaust manifold like the one on my '71 International Travelall with the big AMC 400cid engine.

You could probably machine an adapter block place between any intake and carb on flat-head 6 engines, and just about any other engine, but the orifice restriction would have to be so small as to make it nothing more than an "innovative looking ornament."

[Gunslinger]

If you look at many, if not most, PCV vales, the piece that moves internally usually has a number stamped in it. The numbers have different meaning for different engines and the correct application. PCV vales aren't a one size fits all proposition. They're designed specifically for each engine application and specs of the engine. I don't know what the scientific formula the engineers use to arrive at the specs for each PCV valve, but they are engine specific.

[StudeRich]

No "small" orifice required IN THE ADAPTER, the GM Engineered "AC" Calif. retrofit kits had an adapter just like you mention for all 6's and V-8 Studes and all other makes that was Bake-a-lite and had a full 3/8" port in and out, most also included the "upper crankcase" system for sealing one oil filler cap on V-8's and drawing crankcase air from the other or the Valve Cover and into the Air Cleaner for high speed flow or when the lower system was under low vacuum as in acceleration.

The controlled size orifice was built into the PCV Valve.